Skin care fabric having a heterogeneous frictional property

ABSTRACT

A fabric system which can provide a skin care effect and which is comprised of first and second faces, a first face having a lower coefficient of friction than a second face, is disclosed.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates generally to a fabric system which can provide a skin care effect and which is comprised of first and second faces, a first face having a lower coefficient of friction than a second face.

Discussion of the Background

Anti-aging products and services, including skin care are an active concern and are projected as growth industries, in-part driven by the aging of Baby boomer and Generation X segments of the populations.

In addition, sleep problems in the United States are remarkably widespread, affecting roughly three out of four American adults, according to research by the National Sleep Foundation (NSF). Consequently, a great deal of attention has been paid to the circumstances surrounding poor sleep, along with strategies for how to improve it.

Many factors, such as temperature, fabric thread count, weave and moisture wicking properties have been investigated in the area of sleep comfort. While moisture wicking properties have been viewed from the perspective of comfort, fabrics which remove too much moisture can create a drying environment which enhances the appearance of aging.

Further, large amounts of friction experienced between skin and fabric and the irritation associated therewith can increase the appearance of short and long term wrinkles in facial skin.

Sleep represents about 25-33% of a typical person's day, and accordingly sleep associated products offers an opportunity to provide a skin care effect over a substantial period of time.

U.S. Pat. No. 5,888,914 discloses yarns consisting essentially of about 85 to 90 weight % hydrophobic fiber and about 10 to 15 weight % hydrophilic fiber can be made into fabrics that exhibit a combination of properties that make them strongly preferred by wearers, as compared even to fabrics made from yarns containing only 5% more, or 5% less, of the hydrophilic fiber. More particularly, these novel yarns yield fabrics capable of quickly absorbing perspiration from a wearer's skin and yet capable of quickly releasing that moisture, resulting in surprising levels of wearer comfort and wearer preference.

U.S. Pat. Nos. 8,402,580 and 8,566,982 discloses fabric systems, and more specifically to bed coverings constructed of high gauge circular knitted fabrics that accommodate and maintain optimum thermal conditions for sleep, which in turn can lead to faster sleep initiation and deeper, more restorative sleep.

U.S. Pat. No. 9,788,661 describes a knitted performance fabric having a plurality of spaced apart ventilation ports.

U.S. Pat. Nos. 8,993,067 and 8,349,976 discloses compositions for oil- and/or water-repellent finishing of fiber materials.

U.S. 2012/0227185 discloses a fabric arrangement and pillow designed to prevent skin lines and wrinkle formation while improving sleep.

U.S. Pat. No. 5,084,928 discloses a pillowcase which includes at least a first and second section of fabric joined along three sides, each section of fabric having a length and width measurements less than that of the pillow.

Huntsman Textile Effects has reported development of a textile system Everglide™ Low Friction Systems that effectively reduces fabric to skin friction and promotes longer-lasting performance especially for active sports enthusiasts.

In spite of efforts in the area of fabric technology, there remains opportunities to improve skin care and the sleep experience.

SUMMARY OF THE INVENTION

Applicant's invention is directed to a fabric providing a skin care effect comprising first and second faces, a first face having a lower coefficient of friction than a second face.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The fabric according to the invention can provide a skin care effect and is comprised of hydrophilic fibers and hydrophobic fiber, said fabric having a predominantly hydrophobic side having a lower coefficient of friction than the opposite, predominantly hydrophilic side.

The predominantly hydrophobic side, in addition to providing a lower coefficient of friction than the opposite predominantly hydrophilic side, has a reduced tendency to remove moisture than a facially homogenous hydrophilic fabric, such as cotton, and therefore promotes a more moisture rich environment for skin, reducing the effects of aging.

The friction characteristics between fabric and skin may be measured by techniques known to those of ordinary skill in the art such as described by Kanthvadivu et al.

By providing one surface of the fabric having a lower coefficient of friction that the opposite side, a reduced friction fabric surface which contacts skin can reduce the effect of frictional skin damage, which may be manifest in the reduction of the formation of wrinkles.

Hydrophobic Fiber

Hydrophobic fibers are fibers that are relatively non-water absorptive and moisture insensitive. For the purpose of this invention, hydrophobic fibers are those fibers that will absorb from zero to 10 percent of their weight in water. Examples of hydrophobic fibers include nylon, polypropylene, polyesters such as polyethylene terephthalate and polyacrylonitrile. A specific hydrophobic fiber is nylon 6,6.

For the purpose of this invention, the amount of water that fibers will absorb may be measured by weighing the dried fibers, exposing the fibers to conditions of 100% relative humidity and room temperature, for a period of twelve hours, and weighing the fibers to determine the weight % of water absorbed.

In addition to providing hydrophobicity, the hydrophobic fiber can have a further property of a reduced coefficient of friction relative to the hydrophilic fibers.

In one embodiment, hydrophobic fiber is formed into a yarn having a hydrophobic property.

The amount of hydrophobic fiber is generally, 25-45 wt. %, preferably 30-40 wt. %, more preferably 32-38 wt. %, even more preferably 35 wt. %, wt. % being based on the entire weight of fibers of the fabric.

Hydrophilic Fibers

The fabric according to the invention is comprised of hydrophilic fibers. Hydrophilic fibers are those which will absorb at least about 15 percent of their weight in water. Examples of hydrophilic fibers include cellulosic fibers such as cotton and rayon, as well as worsted wool and polyvinyl alcohol. For the purpose of this invention, the amount of water that fibers will absorb may be measured by weighing the dried fibers, exposing the fibers to conditions of 100% relative humidity and room temperature, for a period of twelve hours, and weighing the fibers to determine the weight % of water absorbed.

The hydrophilic fiber component is preferably in amounts of 55-75 wt. %, preferably 59-71 wt. % more preferably 65 wt. % being based on the entire weight of fibers of the fabric.

The hydrophilic fiber may be of a single composition or as a mixture of at least first and second hydrophilic fibers and in such an embodiment of a mixture of at least first and second hydrophilic fibers, the type of fibers and relative amounts may be as follows:

First Hydrophilic Fiber

The first hydrophilic fiber is preferably comprised of a synthetic cellulose based fiber such as rayon which may be prepared by conventional methods known to those of ordinary skill in the art, such as and including nitrocellulose, acetate method, cuprammonium method, viscose method and Lyocell, preferably by the Lyocell method.

Second Hydrophilic Fiber

A second hydrophilic fiber, distinct from rayon, may include natural fibers such as cotton or wool which may be used, preferably cotton is used as the second hydrophilic fiber.

The hydrophilic fiber component is preferably comprised of first and second hydrophilic fibers in amounts of 40-50 wt. %, preferably 42-48 wt. % more preferably 45 wt. % of the first hydrophilic fiber and 15-25 wt. %, preferably 17-23 wt. % more preferably 20 wt. % of the second hydrophilic fiber, wt. % being based on the entire weight of fibers of the fabric.

A weight ratio of first and second hydrophilic fibers is 4:1 to 1:2, preferably 3:1 to 1:1.5, more preferably 2.5-1.8:1 and most preferably 2.25:1.

In one embodiment, first and second hydrophilic fibers are formed into a single yarn from an intimate blend of first and second hydrophilic fibers, the yarn having a hydrophilic property.

Fabric

The yarns of hydrophobic fibers and yarns of hydrophilic fibers can be made into a textile material by conventional means such as by weaving and knitting. The fabric according to the invention is thus comprised of two separate yarns, one exhibiting hydrophobic properties and a lower coefficient of friction relative to the hydrophilic fibers and one yarn exhibiting hydrophilic properties. By adjusting the surface area exposure of hydrophobic yarn and hydrophilic yarn, a heterogeneous frictional property may be obtained.

A single layer of fabric is comprised of two faces, a first face having a lower coefficient of friction than a second face. Two faces, a first face having a lower coefficient of friction than a second face is achieved in a single layer of fabric and may exclude two or more layers of fabric in achieving a first face having a lower coefficient of friction than a second face.

Further a heterogeneous frictional property is achieved in the absence of heterogeneous surface treatment. A heterogeneous frictional property is preferably achieved by adjusting the relative exposure of hydrophobic yarn and hydrophilic yarn.

Other fibers may be incorporated into the fabric to obtain desired properties so long as a heterogeneous frictional property is maintained. For example, the fabric may contain about 5 to about 10 wt. % based on the entire weight of fibers of the fabric of a continuous elastomeric filament (such as Lycra® elastomer fiber, DuPont Company, Wilmington, Del.) incorporated into the fabric to provide stretch and recovery properties.

When woven, the fabric of the invention will generally have a thread count (threads per inch) of from 250 to 450, preferably 300 to 400 more preferably about 300-325.

In the embodiment of a knit fabric, the fiber composition is 40-60 wt. % of hydrophobic fiber and 40-60 wt. % of hydrophilic fiber, more preferably 45-55 wt. % of hydrophobic fiber and 45-55 wt. % of hydrophilic fiber and most preferably 50 wt. % of hydrophobic fiber and 50 wt. % of hydrophilic fiber. In a knit fabric embodiment, the hydrophobic fiber comprises nylon and the hydrophilic fiber comprises rayon.

The fabrics may be dyed and finished in a conventional manner as described in references such as T. Ishida, An Introduction to Textile Technology, and J. H. Marvin, Textile Processing, cited above.

A first face of the fabric according to the invention is woven in order to expose a greater surface area of hydrophobic fiber having a lower coefficient of friction than on the second face, the second face exposing a greater surface area of hydrophilic fiber than on the first face and thus, having a greater coefficient of friction, using weaving techniques known to those of ordinary skill in the weaving art.

The fabric according to the invention may be prepared by knitting yarns of hydrophilic fibers and yarns of hydrophobic fibers to provide for heterogenous faces.

In one embodiment, in a first face, at least 60%, preferably at least 70%, more preferably at least 80%, even more preferably at least 90% and up to 100% of the exposed surface area of the face is exposed as hydrophobic fiber. The percentage of expose surface area is determined by the exposed percentage surface area as a hydrophobic fiber.

The fabric according to the invention is comprised of first and second faces exhibiting heterogeneous frictional properties. In a preferred embodiment, the first face of fabric has a coefficient of friction which is 5% lower, more preferably 10% lower, even more preferably 20% lower, even more preferably 30% lower, even more preferably 40% lower and most preferably 50% lower than the coefficient of friction of the second face.

In a preferred embodiment, the first face of the fabric exposing a greater surface area of hydrophobic fiber and exhibits a coefficient of surface friction against human skin of from 0.100 to 0.150 μm preferably from 0.105 to 0.140 μm. more preferably from 0.106 to 0.130 μm, using the technique of Mari Inoue (2011). Surface Friction Pro Ways, Dr. Taher Ghrib (Ed.), ISBN: 978-953-307-206-7.

Concurrent with the coefficient of surface friction exhibited by the first face of the fabric exposing a greater surface area of hydrophobic fiber, the second face of the fabric exposing a greater surface area of hydrophilic fiber exhibits moisture management property as measured by at least one of breatheability according to ASTM E96, absorption/wicking using a gravimetic absorbancy testing system, moisture migration/wicking according to AATCC 195, Evaporation according to AATCC 201.

The properties of fabric surface hydrophobicity and coefficient of surface friction may be measured as an aggregate property of a sample 4″×4″.

Fabric according to the invention may be evaluated for Hand/comfort according to the Kawabata Evaluation system, known to those of ordinary skill in the art. The Kawabata Evaluation System (KES) is a series of instruments used to measure those textile material properties that enable predictions of the aesthetic qualities perceived by human touch. KES instruments quantify garment material tactile qualities through objective measurement of the mechanical properties related to comfort perception. With low forces applied, as in manipulating/touching fabrics, the Kawabata instruments define the role played by tensile (stretch), shear stiffness (drape), bending rigidity (flexing), compression (thickness, softness), and surface friction and roughness (next to skin) on tactile sensations. This analytical power, combined with the capability to characterize energy loss in mechanical deformation and recovery processes, provides an unparalleled tool for use in fabric hand analysis. KES provides a unique capability, not only to predict human response, but also to provide an understanding of how the variables of fiber, yarn, fabric construction and finish contribute to perceptions of comfort.

The fabric according to the invention may be used to form a bed sheet or a pillow case. The dimensions and construction of a bed sheet are well known to those of ordinary skill in the art and may be flat or fitted. In a preferred embodiment the bed sheet is provided with an indicator differentiating the first and second sides in terms of coefficient of friction allowing the user to orient the surface of the bed sheet having a lower coefficient of friction, to contact their skin when in use.

In some embodiments, bed sheet is configured to cover all or a portion of a top surface of a mattress. In some embodiments, bed sheet is configured to be larger than the top surface of the mattress such that at least a portion of bed sheet covers all or a portion of a side surface of the mattress. In some embodiments, bed sheet has substantially the same size and shape as the top surface of the mattress. In some embodiments, the mattress is a standard size mattress, such as, for example, a twin mattress, a full mattress, a queen mattress, a king mattress, or a California king mattress. In some embodiments, the mattress is a crib mattress. In some embodiments, the mattress is a memory foam mattress, an orthopedic mattress (with or without springs), a foam mattress, a mattress that includes gel, a crib mattress, a couch mattress or lounge pad.

Bed sheet extends from a top surface to an opposite bottom surface and from a side surface to an opposite side surface. Side surfaces each extend between top and bottom surfaces. The bed sheet has a length L defined by the distance from top surface to bottom surface and a width W defined by the distance from side surface to side surface. In some embodiments, length L is about 96 inches. In some embodiments, length L is about 102 inches. In some embodiments, length L is about 106 inches. In some embodiments, length L is between about 96 inches and about 106 inches, such as, for example, about 97 inches, about 98 inches, about 99 inches, about 100 inches, about 101 inches, about 102 inches, about 103 inches, about 104 inches, or about 105 inches. In some embodiments, length L is greater than 106 inches. In some embodiments, width W is about 71 inches. In some embodiments, width W is about 86 inches. In some embodiments, width W is about 96 inches. In some embodiments, width W is about 105 inches. In some embodiments, width W is about 110 inches. In some embodiments, width W is between about 71 inches and about 110 inches, such as, for example, about 72 inches, about 73 inches, about 74 inches, about 75 inches, about 76 inches, about 77 inches, about 78 inches, about 79 inches, about 80 inches, about 81 inches, about 82 inches, about 83 inches, about 84 inches, about 85 inches, about 86 inches, about 87 inches, about 88 inches, about 89 inches, about 90 inches, about 91 inches, about 92 inches, about 93 inches, about 94 inches, about 95 inches, about 96 inches, about 97 inches, about 98 inches, about 99 inches, about 100 inches, about 101 inches, about 102 inches, about 103 inches, about 104 inches, about 105 inches, about 106 inches, about 107 inches, about 108 inches, or about 109 inches. In some embodiments, width W is greater than about 76.5 inches. In some embodiments, width W is greater than about 110 inches.

The bed sheet may also be affixed to a baby mattress, the dimensions for which to accommodate a baby mattress being clear to those of ordinary skill in the art.

In another embodiment, the fabric according to the invention may be provided in the form of a sleep mask, the face of the fabric which contacts the skin having a lower coefficient of friction than the opposite face.

The hydrophobic fiber of the fabric according the invention may further comprise a biomineral, impregnated therein.

The design and configuration of a sleep mask is generally known to those of ordinary skill in the art and is comprised of a face plate configured to cover predominantly the eyes of a human face, leaving at least a portion of the forehead and nose exposed and is provided with a strap or fastening mechanism to allow for attachment to the face. The sleep mask may be equipped with eye cavities so that the eyes do not touch the face plate. The sleep mask will generally block at least 90%, preferably at least 95%, more preferably 98% and most preferably 100% of ambient light.

The face plate of the sleep mask may be comprised of first and second fabric layers, which may be fused and may be configured to contain an insert.

Additional embodiments of applicant's fabric may be in the form of articles such as clothing, sleepwear, under garments, robes, duvet covers and spa linen. The fabrication of such articles in which the first face having a lower coefficient of friction is primarily disposed to contact skin when in use, is within the level of skill of those of ordinary skill in the art.

Having generally described this invention, a further understanding can be obtained by reference to certain specific examples which are provided herein for purposes of illustration only and are not intended to be limiting unless otherwise specified.

Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein. 

What is claimed as new and desired to be secured by Letters Patent of the United States is:
 1. A fabric comprising: a hydrophilic yarn comprising hydrophilic fibers; and a hydrophobic yarn comprising hydrophobic fibers, wherein said fabric is comprised of first and second faces, said first face having a lower coefficient of friction than said second face.
 2. The fabric according to claim 1, wherein said first face of fabric has a coefficient of friction which is 5% lower than a coefficient of friction of the second face.
 3. The fabric according to claim 1, wherein said first face has a coefficient of friction which is 10% less than said second face.
 4. The fabric according to claim 1, comprising 25-45 wt. % of hydrophobic fiber, wt. % being based on the entire weight of fibers of the fabric.
 5. The fabric according to claim 1 wherein said hydrophilic yarn is comprised of a first hydrophilic fiber comprising rayon and a second hydrophilic fiber comprising cotton.
 6. The fabric according to claim 5, wherein said first hydrophilic fiber comprises fibers prepared by the Lyocell method.
 7. The fabric according to claim 1, wherein said hydrophobic fiber comprises nylon.
 8. The fabric according to claim 5, wherein a weight ratio of first and second hydrophilic fibers is 2.5:1 to 1:2.
 9. The fabric according to claim 5, wherein said first hydrophilic fiber is present in an amount of 40-50 wt. % said second hydrophilic fiber is present in an amount of 15-25 wt. % wt. % being based on the entire weight of fibers of the fabric.
 10. The fabric according to claim 1, wherein said first face exhibits a coefficient of surface friction against human skin of from 0.100 to 0.150 μm.
 11. The fabric according to claim 1, wherein said fabric is woven.
 12. The fabric according to claim 1, wherein said fabric is knit.
 13. The fabric according to claim 1, wherein a heterogeneous frictional property is achieved in the absence of heterogeneous surface treatment.
 14. The fabric according to claim 1, wherein a heterogenous frictional property is achieved based on the relative exposure of hydrophobic yarn and hydrophilic yarn.
 15. A bed sheet comprising the fabric according to claim
 1. 16. A sleep mask comprising the fabric according to claim 1, wherein said sleep mask is configured such that a face of said fabric having a lower coefficient of friction contacts facial skin when in use.
 17. The article selected from the group consisting of clothing, sleepwear, an undergarment, a robe, a duvet cover and spa linen comprising the fabric of claim 1, wherein said first face having a lower coefficient of friction than said second face is oriented towards skin when in use. 